Its Guess the Wishbone Time!
Simon S - 21/9/07 at 07:12 PM
Hi Folks,
Got hold of a set of wide track wishbones, but my question is what uprights are the upper wishbones suitable for, Cortina or Sierra? Wishbone
dimensions are 250mm from the inboard pivot centre to the tip of the bush tube to hold the upright ball joint, the inboard (chassis end) bush tubes
are 228mm from one outer edge to the other and the ball joint pivot centreline intersects the inboard bush tube centreline to split it 89mm/139mm.
(sketch in my photo archive as wasn't sure how to attach it to the post)
Any ideas? I am having trouble getting confirmation that these are for Cortina uprights rather than Sierra ones.
Cheers!
Rescued attachment wishbone.jpg
ecosse - 21/9/07 at 07:32 PM
Depends on the size of the bottom bone as to what upright they will fit
Avoneer - 21/9/07 at 08:09 PM
It's the top one that matters.
The bottom can be in the same place on Sierra and Cortina, but it's the top one that matters as the offset of the top ball joints are
different.
Pat...
ecosse - 21/9/07 at 08:12 PM
quote:
Originally posted by Avoneer
It's the top one that matters.
The bottom can be in the same place on Sierra and Cortina, but it's the top one that matters as the offset of the top ball joints are
different.
Pat...
That works both ways though doesn't it?
especially if the bones are not standard size, no way to tell without knowing what size the bottom one is 
Cheers
Alex
Simon S - 22/9/07 at 06:53 AM
Gents,
I had assumed that the top wishbone would identify its target upright based on its geometry and hence its induced castor angle, which is different
between the Cortina & Sierra.
Looking at the bottom wishbone size it has an inboard bush tube centre to end of balljoint pivot tube distance of 440mm, exactly 100mm greater than
the Cortina based 'book' design.
The top Cortina based 'book' wishbone design dimension for this is 175mm, and the new wishbone in question being 250mm is not an equivalent
100mm greater in induced track increase.
Does this alone point to the wishbone being for Sierra? If someone can comment on the geometry and induced castor angle I think that would seal
it.
Cheers,
Simon
ecosse - 22/9/07 at 09:23 AM
quote:
Originally posted by Simon S
Gents,
I had assumed that the top wishbone would identify its target upright based on its geometry and hence its induced castor angle, which is different
between the Cortina & Sierra.
Looking at the bottom wishbone size it has an inboard bush tube centre to end of balljoint pivot tube distance of 440mm, exactly 100mm greater than
the Cortina based 'book' design.
The top Cortina based 'book' wishbone design dimension for this is 175mm, and the new wishbone in question being 250mm is not an equivalent
100mm greater in induced track increase.
Does this alone point to the wishbone being for Sierra? If someone can comment on the geometry and induced castor angle I think that would seal
it.
Cheers,
Simon
I'm not 100% on this but I thought that the sierra required a shorter (than book) size bone for the same length bottom bone?
I'm sure there was a thread about the differences, although I'm struggling to find it now 
Cheers
Alex
Avoneer - 22/9/07 at 10:41 AM
Using book bones, the top bone needs to be shorter for the Cortina - I think.
Hmmmm.
Pat...
Sorry - everything I think is complete contradiction to ecosse - no offence.
ecosse - 22/9/07 at 03:12 PM
quote:
Originally posted by Avoneer
Sorry - everything I think is complete contradiction to ecosse - no offence.
LOL...no worries Pat
Cheers
Alex
